“Basically, the DC universe is a piece of music,” the acclaimed Scottish writer told the “Multiversity Enroll” panel Friday afternoon at Comic-Con International in San Diego. “All the worlds vibrate at different wavelengths and pitches, and if you get them all together, it’s a song …”

Then he added, to laughter, “probably something by Lady Gaga.”

“It’s a comic book, and it sings,” he said.

Musical structure is the basis for the storytelling of the long-in-the-works “Multiversity” event from the comics savant behind such original mind-benders as “The Invisibles” and “Flex Mentallo: Man of Muscle Mystery” and visionary looks at DC characters, including “Doom Patrol,” “All-Star Superman” and a seven-year run on Batman titles that concluded last year.

Sporting a black long-sleeve shirt bearing the word “Evil” in cursive – and kicking off the presentation by declaring, “I’m the evil version of Grant from Earth-3” – Morrison led fans through an introductory Multiversity 101 survey of some upcoming Earths they’ll see in depth in the series.

Nix Uotan is on the front lines against the coming threat. (DC Entertainment)

The story has its roots in a long tradition of alternative-reality tales at DC. Morrison pointed to the Gardner Fox-written, Carmine Infantino-drawn “Flash of Two Worlds” story from 1961’s “The Flash” No. 123, in which Barry Allen discovers that the comic-book character from his youth he’d named his superhero persona after is real in an alternative universe – and that he can get to that reality by vibrating. It was the vibration element that set Morrison on the path toward “Multiversity,” and he said that “Flash of Two Worlds” was the first parallel-worlds story to show a superhero reading a comic book.

“I thought, ‘Well, what if … something so monstrous, so evil, so devastating decided to attack the entire multiverse, and the only way they could communicate with each other about the danger was to write comic books about them?’”

Issues of “Multiversity” will feature characters reading comics of the previous issue. “Multiversity” Nos. 1 and 2 are the framing issues of the larger story, with a variety of other No. 1’s. The art on the debut issue is by Ivan Reis and Joe Prado.

Morrison also touched on some of the concepts in the 2008 DC story line “Final Crisis,” including having Superman sing at an enemy, and that story’s Nix Uotan figures into the new saga.

Uotan, the last of the multiverse-protecting Monitors, and his chimpanzee companion are the first line of defense against the coming threat. The “Multiversity” cast also includes the aboriginal storm god Thunderer (now actually aboriginal, remade from an earlier white version).

Morrison said he became fascinated by some of Marvel legend Stan Lee’s comics directly addressing readers (and broke into a Lee impression). He talked about a technique of “hypnotic induction and the notion that a comic that talks to you can really … you up. This is a dangerous book.”

After the first issue, the next installments visit different worlds in the multiverse.

“Multiversity: Society of Super-Heroes” No. 1, with art by Chris Sprouse and due in September, features Doc Fate (a sort of combination of Doctor Fate and Doc Savage, Morrison said), the Atom, Blackhawk and a version of Abin Sur (who gave the Green Lantern ring to Hal Jordan and is, in this version, hesitant to appear on Earth because he looks like the devil), and there’s fighting against zombie paratroopers, all on Earth-20.

Following that is “Multiversity: The Just,” set on Earth-16 with art by Ben Oliver. It focuses on second-generation superheroes bored by a world where their parents already solved the problems – the kids re-enact battles for fun. It looks at “what happens to superheroes when there’s nothing to do,” Morrison said. There’s trouble between the son of Batman – Damian Wayne, a character Morrison memorably revived in the mainstream Bat-mythos — and the son of Superman when the former dates Alexis Luthor, daughter of the man who killed the latter’s father. When things go wrong, will the kids be as capable as their parents were?

The Frank Quitely-drawn “Multiversity: Pax American” No. 1 is the fourth episode, and stars old Charlton Comics characters that DC acquired (and that inspired Alan Moore and Dave Gibbons’ landmark “Watchmen”). It’s a “political, cosmic, philosophical piece,” Morrison said, exploring why the Peacemaker (the character that led to “Watchmen’s” Comedian) assassinated the president of the U.S. – working backward in time to explain the event.

Artist Cameron Stewart was on hand to talk about the issue he worked on, “Multiversity: Thunderworld,” which features Shazam. He said he didn’t want to do a “flat-out emulation of C.C. Beck … but I wanted to have that same effect.”

Morrison said “Thunderworld” is an “all ages, Pixar-movie version of Shazam,” and that it features the classic Shazam foe Doctor Sivana – a major bad guy in the overall story – who is duplicating magic via technology.

A guidebook to “Multiversity” comes after “Thunderworld,” with a story component featuring Jack Kirby’s Kamandi, and a Morrison-written, Ryan Hughes-drawn map showing each of the 52 worlds – and the panel’s moderator, DC’s John Cunningham, pointed out the publisher has never before formally defined each Earth of the multiverse.

“After all these years, you guys deserve that,” Morrison said to laughter. He also pointed out that, on the map, a world you might think of as the Stan Lee world is directly opposite the Jack Kirby world.

Panel attendees received posters of the map of the multiverse – which Cunningham said that, other than some promotional ones produced for comics retailers, will not be available.

The map lays out territory that other creators can play in.

Ultimately, Morrison said, “We want to make sure every single universe is capable of sustaining its own book” because he felt some past multiverse stories wasted entire universes. “This is not cannon fodder for the next crisis.”

He pointed to Earth-33 on the map and told the crowd, “You are here. That’s us.”